The subject invention relates, generally, to power table saws and, more specifically, to a safety device for holding the material being cut by said saw to the table on which the saw is mounted and whereupon the operation takes place. It is an important object of this invention to keep boards from kicking back toward the operator during the sawing process.
When cutting, ripping or otherwise shaping boards on table-mounted rotary saws or shapers, a kickback of the piece occurs when the saw blade becomes hung in the board whereupon the board is rapidly propelled backward into the operator. In the past, users of power table saws have used blocks of wood to hold the piece in place and to push the piece through the rotating saw. Such makeshift devices have proved to be inadequate for retaining the boards during an entire cut and, especially, have not solved the problem, in very long cuts, of holding material in place while the operator walked around the saw to pull the piece through the machine.
Various devices and methods have been developed in the past to try to alleviate the problem of kickback. U.S. Pat. No. 2,676,625 describes a device having a series of upper and lower rollers disposed from a header on either side of the saw blade together with pivotally mounted finger elements for restraining the board. U.S. Pat. No. 4,212,214 describes an antikickback device for use with radial arm saws and requiring a splitter portion to prevent binding. U.S. Pat. No. 2,823,711 describes an adjustable splitter blade assembly for preventing kickback in table saws. None of the foregoing patents anticipate the subject invention wherein two board-restraining components removeably attached to a standard table rip fence of a conventional table saw at variable predetermined positions fore and aft of the saw blade and having safety shields disposed therein provide, not only absolute board-restraining capability, but full assurance against kickback.